When assembling a car, and in particular a car having a transversely-mounted engine, a flexible coupling needs to be provided between the exhaust manifold which is fixed to the engine and the exhaust pipe which is fixed to the bodywork which supports the silencer or muffler.
In order to take up relative movement between the manifold and the exhaust pipe, and in order to provide sealing, one of the lengths of tubing is terminated by a convex spherical bearing surface made at the end of the tubing itself or formed by an annular gasket, and co-operating with a complementary surface on the other length of exhaust tubing. In order to hold the parts together, the exhaust manifold and the exhaust pipe are both provided in this case with assembly flanges, each associated with a length of tubing and connected to each other by bolts having thrust springs mounted therearound in order to ensure sealing and coupling.
During relative movement of the two lengths of exhaust tubing, the two spherical surfaces rub against each other and generate vibrations which are extremely disagreeable. The level of such vibrations has already been reduced by providing a special structure for a gasket between the facing ends of the lengths of exhaust tubing. However, the vibrations generated by friction between the various parts of the coupling when in use has not yet been completely eliminated.
Since the generation of vibrations cannot be completely eliminated, an object of the invention is to minimize such vibrations.